Two New Jersey companies are expanding their portfolio of clean-energy projects by acquiring a solar farm in North Carolina and planning to build an onshore wind facility in Pennsylvania.

PSEG Solar Source and NJR Clean Energy Ventures are unregulated subsidiaries of Newark-based Public Service Enterprise Group and New Jersey Resources, both of which have been aggressive in investing in clean-energy projects, most located outside New Jersey’s borders.

With the cost of utility-scale solar farms and wind projects dropping to where they are competitive with conventional ways of generating electricity, many energy companies are increasing investments in renewable energy.

PSEG Solar Source is spending more than $40 million to acquire a 25.9-megawatt solar project from Ecoplexus in Martin County, NC, about 80 miles east of Raleigh. The facility, which has a 15-year power-purchase agreement with Virginia Electric & Power, sits on a 105-acre parcel.

“We are pleased to extend our portfolio into North Carolina and be able to provide clean, reliable energy to power 3,800 homes,’’ said Diana Drysdale, president of PSEG Solar Source.

The farm is the 15th utility-scale project in 11 states owned by the company, with facilities located in Arizona, California, Delaware, Florida, Ohio, Texas, Utah, and Vermont. PSEG Solar Source also has a solar farm in New Jersey at the U.S. headquarters of Mars Snackfood in Hackettstown.

Earlier this month, PSEG Solar Source said it is spending $110 million to buy two solar farms in California and Utah, the latter the largest solar project undertaken by the company at 62.7 megawatts. The latest acquisition will increase the capacity of the company’s portfolio to 241 megawatts. Construction on the project is underway and commercial operations are expected to begin in several months.

NJR Clean Energy Ventures, a subsidiary of Wall Township-based NJR, announced its fourth onshore wind project this week. The Ringer Hill Wind Farm is located along the Pennsylvania-Maryland border in Somerset County. The company plans to invest approximately $84 million to build, own, and operate a 39.9-megawatt facility, which is expected to be operational during the first quarter of 2017.

When complete, NJRCEV’s onshore wind portfolio will total more than 120 megawatts, capable of producing enough energy to power 37,500 homes each year. Its other wind projects are located in Kansas, Iowa, and Montana and all are operational.

“Wind is an increasingly important segment of our nation’s energy mix and we are pleased to do our part to bring renewable energy to the marketplace,’’ said Laurence Downes, chairman and CEO of NJR.

Through the end of 2015, NJRCEV has invested a total of $539 million in solar and onshore wind projects ($147 million).